Thin films of phthalocyanine compounds formed on cleaved surfaces of muscovite by the vacuum-condensation method showed well-defined single-directional orientation when their substrates were preheated at 300°C for one hour and then kept at 150°C. Their electron diffraction patterns were fiber diagrams, the fiber period of which coincided with the unit-cell length of the b-axis of the individual compounds. When the substrates were preheated at 400°C for one hour and then kept at 150°C, the films formed on the muscovite surface were composed of discrete crystals with a different orientation. Electron-diffraction patterns from the films revealed that the b-axis of the crystal was inclined to the substrate surface. The cross-grating patterns of the (h0l) plane were obtained when the inclination of the films was properly adjusted to the incident beam. The unit-cell constants of platinum-phthalocyanine vacuum-condensed on muscovite were revealed to be as follows with the monoclinic space group C2⁄c: a=23.18 Å, b=3.818 Å, c=23.84 Å, and β=91.9 °. Films of Cu-, Co-, Fe-, Ni- and metal-free phthalocyanines exhibited an orientation similar to that of the platinum derivative. High-resolution electron-diffraction patterns revealed that all the compounds assumed a conspicuous isomorphism with one another and occurred in the metastable forms of their dimorphs.

Lattice and atomic structure imaging of semiconductors by high resolution transmission electron microscopy Appl. Phys. Lett. 47, 685 (1985); 10.1063/1.96058 Imaging of the silicon on sapphire interface by highresolution transmission electron microscopyIn order to determine the ultimate molecular resolution attainable with a conventional electron microscope, the direct observation of hexadecachloro-Cu-phthalocyanine molecules was attempted. Since phthalocyanine derivatives are known to form crystalline films with columns of parallel stacks of planar molecules, the specimens were prepared by epitaxial growth on KCI cleavage face through vacuum evaporation so that the column axis was directed almost normal to the thin-film surface holding an orientation suitable for the observation. The molecular orientation was determined by Patterson synthesis based on the laser optical transform of the electron diffraction pattern obtained from the individual crystallites placed on the microgrid mesh. The direct observation was carried out with the lOO-kV electron beam incident on the specimen along the column axis. The crosslike images arrayed in a centered rectangular net were clearly resolved, well representing the molecular shape of phthalocyanine with the configuration like a four-leaf clover. The effect of the spherical aberration and the defocus value for the objective lens are also discussed in relation to the contrast inversion of the total images. It was also found that the chlorinated Cu-phthalocyanine is 40 times more resistant to the electron radiation damage than the ordinary phthalocyanines.

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